It is a common practice in the manufacture of mineral fiber insulation to pass the insulation between a pair of foraminous conveyors, or belts, mounted for travel through the curing oven. Hot gases are passed through the insulation to more effectively cure the binder in the insulation. Associated with the oven are supplies of hot drying and curing gases, usually heated air, which travel generally upwardly or downwardly through the insulation material. Typically, the curing ovens are divided into zones, and flexible seals are sometimes used to prevent the curing gases from passing from one zone to an adjacent zone. The common construction for the conveyors is that of apertured flights connected in series and driven by a chain. The ends of the flights are mounted on wheels which ride in tracks running the length of the oven.
One of the problems with ovens for heating mineral material is that the ovens cannot meet the current capacity demands made upon them. Increases in technology and other parts of manufacturing processes, such as the mineral fiber forming portion of the process have enabled increases in line speed which push existing ovens to their capacity. Furthermore, the recent trend in the glass fiber industry, in particular, has been to reduce fiber diameter. This results in a desire to reduce the flow of curing gases in the oven to avoid structural damage to the mineral fiber insulation.
A simple, but expensive, solution is to extend the length of the oven and add one or more additional oven zones. This is, of course, quite expensive, and in some plant facilities it is physically impossible because of space constraints. Another solution is to increase the temperature of the gases in the first oven zone. In many cases however, the high temperature tolerance of the oven conveyor lubricants provide an upper limit on the temperature of curing gases. There is a need for low cost way to improve the efficiency of ovens for drying and curing fibrous insulation material without requiring large amounts of capital or space.